Surprise! On the eve of a bitter battle to get Obamacare repealed (and replaced, kind of!), Trump announced via Twitter that transgender troops would not be able to serve openly in the U.S. military. The reason? "Our military... cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail," Trump wrote. The "disruption" argument is one that has been used throughout history against many landmark civil rights proposals, as the Washington Post points out. It was used to stop women soldiers from serving in combat roles, and, more broadly, as a blockade for civil rights.
To "disrupt" something, as Merriam-Webster puts it, is to "throw [it] into disorder." Certainly it would be "disruptive" for the military to take steps to ensure that its transgender members were given rights equal to their cis counterparts — because those rights aren't in place at present. (While Obama in 2016 ordered that these rights be put in place in one year, current defense secretary Gen. James Mattis delayed that timeline, and on Wednesday Trump called it off entirely.)
With any transition comes "disorder" in the strictest sense of the word: If present policy is "order," then to toss that aside for a new and unexplored policy is "disorder." Just 10 years ago, it was also thought to be "disruptive" for women to serve in military combat roles, given that, much as with Trump's excuse regarding trans rights, the "order" of the military at present would have to be shifted.
Yet, with this new "order" comes new rights. As Obama noted at the time, in 2013: "When we desegregated our military, it became stronger. In recent years, we ended 'Don't Ask, Don't Tell' and allowed gay and lesbian Americans to serve openly — and it's made our military stronger."
With all stages of women's rights came critics who argued that allowing women the same rights as their male counterparts would be "disruptive." Of women having the right to vote, "it is unwise to risk the good we already have for the evil which may occur," wrote the National Organization Opposed To Women's Suffrage a century ago. In 1914, anti-suffrage activist Grace Goodwin wrote: "The ballot has not proved a cure-all for existing evils with men... We find no reason to assume that it would be more effectual with women."
In other words: If it isn't completely broken, why fix it? How can we guess at what what happen to the system if we did? And: If you disagree, and if the system is already broken, then how could changing it do any good?
Today, these arguments feel illogical to the point of being funny. Unless you're a men's rights activist, you'd argue without pause that any difficulty involved in giving women the vote pales in comparison to their having a right to do so. The reason this seems obvious is because we've had this right in place for almost a century, so any alternative feels fantastical.
In another century's time, if civil rights progress broadly continues, it will seem ridiculous for anybody to reasonably suggest that transgender individuals should not serve in the military, or be limited to any rights that their cis counterparts have. We may still be fighting for trans rights in the same way that we continue to fight for women's rights, but some basic principles will hopefully have been established, and the legal right to serve one's country no matter your gender identity will (hopefully) be one of them.